Please post a packaged workbook (.twbx), the .twb does not include the newsletter.csv data used in the workbook.
See the attached. I rearranged the pills to duplicate the Excel spreadsheet, and changed the % of total into a calculated field so I could set the compute using. A compute using of Table (Down) works here, but if you rearrange blue pills in the view it will return different results because that compute using is dependent on the visual arrangement in the view. An Advanced... Compute Using of LINK, Weekday of m_datora gets the same results, and doesn't have that problem.
For learning more about table calculations and compute using, here's a post with a set of links: